Infrastructure development along the Kiratpur-Manali corridor has reached a major milestone with the launch of construction on Himachal Pradesh's first box tunnel at Thalaut in Mandi district. The ambitious engineering project carries an estimated capital outlay of Rs 200 crore. According to Varun Chari, Project Director at the National Highways Authority of India (NHAI), traffic movement through Thalaut and Aut market areas was originally routed via cut-and-cover structures.
Engineering Redesign Following Natural Calamity
Severe rainfall and landslides during the 2023 natural disaster caused extensive devastation along the corridor, completely destroying the operational cut-and-cover transit passage near Thalaut market. The structural collapse prompted highway planners to re-evaluate the terrain's safety requirements and devise a far more resilient long-term alternative. Following comprehensive technical assessments, NHAI submitted a formal proposal for a reinforced box tunnel, which secured central government approval before ground operations commenced.
Square Profile And Modular Block Construction
While cut-and-cover tunnels and box tunnels share similar functional roles in shielding mountain traffic, they differ fundamentally in design geometry. The box tunnel is engineered with an exact square structural profile, offering greater structural stability against debris. Spanning a total length of 500 metres, this artificial tunnel is being assembled using modular engineering blocks. NHAI has mandated a tight construction timeline, setting a completion target of one year for the entire project.
Traffic Reorganisation And Opening Of Aut Tunnel
Once operational, the box tunnel will anchor a restructured vehicular movement plan for the entire highway segment. All outbound traffic heading toward Kullu and Manali will be routed exclusively through this newly erected 500-metre structure. Conversely, return traffic coming down the valley will continue passing through the legacy tunnel at Aut. Crucially, project management noted that operationalising this new box tunnel remains the essential prerequisite for opening the newly constructed tunnel at Aut to public traffic.
Compensation Package Disbursed Under Court Directives
The devastation of 2023 extended beyond the highway perimeter, severely damaging adjacent residential houses in the vicinity of Thalaut market. Following detailed loss evaluations, NHAI sanctioned a relief and compensation package of Rs 20 crore for impacted residents. From this allocation, Rs 12 crore has already been transferred to the Sub-Divisional Magistrate (SDM) of Bali Chowki for systematic distribution to eligible claimants. Concurrently, the High Court issued directives expediting the commencement of repair works, ordering local administrative authorities to extend comprehensive cooperation to NHAI on all safety fronts.
Halving Travel Duration Between Chandigarh And Manali
The broader Kiratpur to Manali four-lane highway initiative has already dramatically transformed connectivity to the hill state, despite minor unfinished sections still undergoing work. Motorists travelling between Chandigarh and Manali, who previously spent between 8 and 9 arduous hours on the road, now complete the trip in just 4 to 5 hours on the functional stretches. Completion of the remaining segments, including the Thalaut box tunnel, will shave off further travel time and secure year-round resilience.
